Field of the Invention
The present invention relates generally to a method of connecting a cable with a cable connector, and more particularly to an improvement in a method of connecting a cable which has a core wire covered with an insulator with a cable connector which has one or more signal transmitting contacts, with each of which the core wire of the cable is electrically connected.
Description of the Prior Art including Information disclosed Under 37 CFR 1.97 and 37 CFR 1.98
There has been proposed to use often a cable connector with which a cable, such as a coaxial cable having a core wire, an inner insulator covering the core wire, a grounding conductor surrounding the inner insulator and the core wire, and an outer insulator covering the grounding conductor, is electrically connected when a plurality of electrical parts, electrical devices or electrical apparatus are mutually connected through the cable for transmitting signals or the like between the electrical parts, electrical devices or electrical apparatus. Such a cable connector is provided with signal transmitting contacts made of conductive material, with each of which the core wire of the cable is connected.
In the cable connectors proposed previously to be electrically connected with the cable, it is usual that the cable is electrically connected with the cable connector by means of a soldering method wherein the core wire of the cable is soldered to the signal transmitting contact provided in the cable connector. However, when the cable is electrically connected with the cable connector by means of the soldering method, especially in a case the core wire of the cable is selected to be extremely thin and thereupon the signal transmitting contact is provided to be extremely small in the cable connector, such problems that a troublesome operation with scrupulous care is required for soldering the core wire of the cable with the signal transmitting contact provided in the cable connector, it is very difficult to control correctly an appropriate quantity of each of a solder and a flux to be used, the cable is damaged by heat generated by the soldering, and so on, are raised.
Accordingly, for avoiding the above-mentioned problems, there has been also proposed previously a method of connecting a cable with a cable connector wherein a signal transmitting contact provided in the cable connector is so deformed into a predetermined shape that the core wire of the cable is electrically connected with the signal transmitting contact without the soldering method, as disclosed in, for example, the Japanese patent application published before examination under publication number 2007-048696 (hereinafter, referred to as published patent document 1) or the Japanese patent application published before examination under publication number 2008-269840 (hereinafter, referred to as published patent document 2).
In the case where such a previously proposed method as mentioned above is put into practice, in a cable connector which has a housing made of insulating material and a plurality of signal transmitting contacts mounted to stand on the housing and with which a plurality of cables are to be connected electrically, each of the signal transmitting contacts is provided with a forked portion formed into a pair of protrusions opposite to each other at a top end thereof. Then, when the cable is electrically connected with the cable connector, first an insulator covering a core wire of the cable is partially stripped from the core wire and the core wire of the cable bared partially is put between the protrusions of the forked portion at the top end of the signal transmitting contact of the cable connector. Next, the forked portion of the signal transmitting contact with the core wire bared partially and put between the protrusions is so deformed by external force exerted thereon as to cause the protrusions to come close to each other. Thereby, in case of ideal, the core wire bared partially is tightly held between the protrusions of the forked portion at the top end of the signal transmitting contact to be electrically connected with the signal transmitting contact. Consequently, it can be expected that the core wire of the cable is stably connected electrically with the signal transmitting contact of the cable connector without the soldering method.
When such previously proposed method of connecting the cable with the cable connector as disclosed in the published patent document 1 or 2, in which the core wire of the cable bared partially is put between the protrusions of the forked portion at the top end of the signal transmitting contact of the cable connector and then the forked portion of the signal transmitting contact is so deformed by external force exerted thereon as to cause the protrusions to come close to each other so that the core wire of the cable bared partially is held by the protrusions to be electrically connected with the signal transmitting contact of the cable connector, is put in practical use, it is feared that the following problems are raised.
In general, the core wire of the cable is formed into a twisted conductive string made by twisting a plurality of conductive fine lines. In the method of connecting the cable with the cable connector disclosed in the published patent document 1 or 2 and put in practical use, the twisted conductive string constituting the core wire of the cable is crushed to become disentangled conductive fine lines when the core wire is tightly held between the protrusions of the forked portion at the top end of the signal transmitting contact of the cable connector. As a result, the electrical connection of the core wire of the cable with the signal transmitting contact of the cable connector is made unstable to be lacking in certainty.
Further, in the case where the method of connecting the cable with the cable connector disclosed in the published patent document 1 or 2 is put in practice, each of the signal transmitting contacts mounted to stand on the housing of the cable connector is formed on an end portion of a metallic plate member to have the forked portion formed into the protrusions opposite to each other at the top end thereof. The thickness of the metallic plate member is subjected to a limit in proportion to the size of the signal transmitting contact and therefore the metallic plate member constituting the signal transmitting contact is unavoidably selected to be relatively thin Consequently, for example, if the external force exerted on the forked portion of the signal transmitting contact for deforming the same to cause the protrusions to become close to each other acts in an inappropriate direction sifted slightly from an appropriate direction, the signal transmitting contact is lacking in strength and comes down on the housing of the cable connector. As a result, the core wire of the cable cannot be correctly held between the protrusions constituting the forked portion of the signal transmitting contact.